Swim fin



FIG. 1 is a top and left side perspective view of a swim fin showing mynew design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a front elevational view thereof;

FIG. 4 is a rear elevational view thereof;

FIG. 5 is a right side elevational view thereof; and,

FIG. 6 is a bottom plan view thereof.

The ornamental design for a swim fin, as shown and described.